title: Postoperative serum troponin T concentration in patients undergoing aortic valve replacement does not predict early postoperative outcome.
abstract: BACKGROUND
  The measurement of serum cardiac troponin T concentration (cTnT) after aortic valve replacement (AVR) provides the opportunity to assess the degree of myocardial damage and may have some prognostic value.
  
  
  OBJECTIVE
  To determine whether elevated troponin level is related to patient outcome.
  
  
  METHODS
  We investigated patient outcome and postoperative serum concentration of troponin T in 79 patients who underwent AVR. Serum levels of cTnT were measured within 24 h of AVR. We searched for the occurrence of subsequent adverse events i.e. requirement for intraaortic ballon pump (IABP) or inotropic support, prolonged Intensive Care Unit (ICU) stay, and in-hospital death.
  
  
  RESULTS
  Serum concentration of cTnT after AVR increased significantly compared to the preoperative value. We found significant positive correlations between aortic cross-clamp time (r = 0.23, p = 0.04), cardiopulmonary bypass time (r = 0.4,p = 0.00029), duration of the surgery (r = 0.30, p = 0.008), and postoperative cTnT level. Three (4%) patients required IABP support, 37 (46%) patients required inotropic support, and 11 (14%) patients had a prolonged ICU stay (> 48 h). Thirty eight (48%) patients required either inotropic support or IABP insertion. At least one adverse event occurred in 44 (56%) patients. Median postoperative serum cTnT concentration was 0.31 ng/mL (interquartile range 0.23-0.60 ng/mL). We failed to find a statistically significant difference in postoperative cTnT level between patients with and without adverse events. According to multiple logistic regression analysis, the postoperative serum level of troponin T was not independently associated with adverse patient outcome. Diabetes mellitus, patient age and left ventricular ejection fraction below 50% were significant independent predictors of adverse events after AVR. The area under receiver operating curve (AUROC) for postoperative serum troponin T concentration as a determinant of various adverse outcomes was never significantly different from 0.50.
  
  
  CONCLUSIONS
  Serum cTnT concentration is frequently - if not universally - elevated after AVR. Serum level of troponin T measured on the first postoperative morning is a poor predictor of patient outcome after AVR and should not be relied on when planning postoperative care.
authors.forename: Magda Lucyna
authors.initials: ML
authors.lastname: Piekarska
authors.forename: Bartosz
authors.initials: B
authors.lastname: Szurlej
authors.forename: Tomasz
authors.initials: T
authors.lastname: Latusek
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Wdowik
authors.affiliation: Medical University of Silesia in Katowice. mdeja@sum.edu.pl.
authors.forename: Marek Andrzej
authors.initials: MA
authors.lastname: Deja
mesh_terms: D000368:Aged; D001022:Aortic Valve Insufficiency / Q000601:surgery*; D001024:Aortic Valve Stenosis / Q000601:surgery*; D019540:Area Under Curve; D015415:Biomarkers / Q000097:blood; D005260:Female; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects*; D006801:Humans; D016015:Logistic Models; D008297:Male; D011183:Postoperative Complications / Q000097:blood* / Q000209:etiology; D011237:Predictive Value of Tests; D016896:Treatment Outcome; D020107:Troponin T / Q000097:blood*
chemical_list: D015415:Biomarkers; D020107:Troponin T